Clean-up duplicated PathInternal files

[jozkee]

There were files named PathInternal*.cs under the libraries/Common/src/System/IO folder, while at the same time we have PathInternal*.cs files under libraries/System.Private.CoreLib/src/System/IO, the content in both files was more or less identical.

This PR removes duplicity by deleting/moving the files in Common to the other folder.

[ghost]

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Issue Details

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There were files named PathInternal*.cs under the libraries/Common/src/System/IO folder, while at the same time we have PathInternal*.cs files under libraries/System.Private.CoreLib/src/System/IO, the content in both files was more or less identical.

This PR removes duplicity by deleting/moving the files in Common to the other folder.

Author:	Jozkee
Assignees:	Jozkee
Labels:	area-System.IO
Milestone:	7.0.0

[jkotas]

Would "$(CommonPath)System\IO\PathInternal.* be more appropriate place for these files?

These files do not contain public APIs. I think we only use CoreLib includes for files with public APIs, and only include them for legacy TFM configurations.

[carlossanlop]

LGTM. I think Jan's suggestion makes sense to move the file to the other location.

[carlossanlop]

We also wanted to merge the *.Win32.cs files into the *.Windows.cs files. Do you plan on doing that separately?

[jozkee]

We also wanted to merge the *.Win32.cs files into the *.Windows.cs files. Do you plan on doing that separately?

Yes, separate; but I think that's a broader issue that not just affects System.IO space.

[carlossanlop]

Last commit LGTM.